Carpets produced from synthetic or natural fibers and mixtures thereof are commonly used in residential and commercial applications as a floor covering. Various types of fibers can be used in making carpets such as polyamide fibers, polyester fibers as well as wool, cotton or even silk.
Carpets, irrespective of whether they are made from natural or synthetic fibers are all prone to soiling and staining when contacted with many household items. Indeed, fibers may become soiled as a result of various items like foods, grease, oils, beverages as well as dirt particles, clay, dust, particulate soils in general, coming into contact with and adhering to the fibers of the carpets. These latter soils often appear in the form of a diffuse layer of soils rather than in the form of spots and tend to accumulate particularly in the so called "high traffic areas" such as near doors as a result of intensive use of the carpets in such areas.
There are a number of carpet cleaning compositions described in the art for removing stains and/or soils from carpets. However, these compositions leave a lot of residues on the carpets after having been applied and left in contact with said carpets to perform their cleaning action. The residues left onto said carpets by said carpet cleaning compositions have the tendency to stick to said carpets and are thus difficult to remove by mechanical means for example by vacuum cleaning. The presence of high amount of residues and in particular of sticky residues, contributes to facilitate carpet resoiling and to make the carpet lose its "new" aspect and colour brightness.
Thus the object of the present invention is to provide a method of cleaning carpets whereby the amount of residues left onto said carpets after having been applied thereto is reduced. A further object of the present invention is to provide a method of cleaning a carpet that provides excellent stain removal performance without the need of removing from said carpet the carpet cleaning composition that has been applied thereto to clean said carpet.
It has now been found that the above object can be met by incorporating an amine oxide surfactant according to the formula R1R2R3NO, wherein each of R1, R2 and R3 is independently a saturated substituted or unsubstituted, linear or branched alkyl group of from 1 to 30 carbon atoms, and/or an acyl sarcosinate surfactant according to the formula: ##STR1## wherein M is hydrogen or a cationic moiety and wherein R is an alkyl group of from 9 to 20 carbon atoms, in a carpet cleaning composition. Indeed, it has now been found that the use of such a surfactant in a carpet cleaning composition allows to reduce the amount of residues left onto a carpet that has been contacted with said carpet cleaning composition. It has further been found that the residues left are at least partially crystals with an average particle surface bigger than 300.mu..sup.2. More particularly, the present invention is based on the consumer noticeable finding that excellent stain removal performance is delivered with a composition comprising such an amine oxide surfactant and/or acyl sarcosinate surfactant without the need of removing said composition from the carpet after having been applied thereto and having performed its cleaning action. Thus the present invention allows a one step carpet cleaning method with excellent stain removal performance. Furthermore, if a removing step although not necessary is nevertheless carried out by for example vacuum cleaning said carpet after having applied thereto said composition, said removing step is facilitated. Indeed, the residues left onto a carpet when cleaned with a carpet cleaning composition according to the present invention can be easily removed from said carpet, for example by vacuum cleaning, as compared to the residues left onto said carpet when cleaned with the same composition without said surfactant according to the present invention, or with the same composition but with alkyl sulphate instead of said surfactant according to the present invention.
An advantage of the present invention is that it is applicable to all carpet types, especially delicate natural fibers and is also safe to all carpet dye types, particularly sensitive natural dyes used therein. The compositions suitable to be used herein are also particularly efficient to clean upholstery and car seats covering.
Another advantage is that the compositions to be used according to the present invention may be applied directly on the carpet without causing damage to the carpet. In addition the cleaning action of the invention commences as soon as the carpet cleaning composition has been applied to the surface. Indeed, the use of the carpet cleaning compositions of the present invention does not necessarily require rubbing or/and brushing of the carpet.
A further advantage of the present invention is that excellent stain removal performance is provided on a variety of stains including particulate stains like clay, dirt, dust, mud, concrete, greasy/oily stains like make-up, lipstick, dirty motor oil, mineral oil, greasy food like mayonnaise and spaghetti sauce, bleachable stains like tea, wine, grass and coffee as well as enzymatic stains like blood.
Yet another advantage of the preferred embodiment of the present invention where said carpet cleaning method is carried out without removing said carpet cleaning composition from a carpet after having been applied and left to dry onto said carpet, is that when said carpet cleaning composition further comprises a perfume, said perfume is longer lasting on carpets. This results in improved fragrance odor of carpets being cleaned. In other words, the method of cleaning carpets according to the present invention wherein the carpet cleaning composition used further comprises a perfume and wherein said composition is not removed from said carpets after having been applied thereto, provides a fresh and clean impression to carpets.